JP2919698B2 - Centerless grinding method for stepped shafts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for centerless grinding of a stepped shaft, in which a cutting tool is cut without interrupting a grinding operation to correct a surface shape of an adjustment wheel.

[0002]

2. Description of the Related Art When a rough processed workpiece 1 is ground by a centerless grinding method to finish a stepped shaft having a predetermined stepped shape, as shown in FIG. 5, the stepped shaft corresponds to the stepped shape of the stepped shaft. The work piece 1 is supported between the adjustment wheel 2 and the receiving plate 4 using the shape adjustment wheel 2 and the grinding wheel 3, and the grinding wheel 3 is controlled while controlling the rotation of the work 1 by the adjustment wheel 2.
Work 1 is ground by

In this case, the workpiece 1 has a large diameter portion 1a and a small diameter portion 1a.
1b, there is a peripheral speed difference between the large diameter portion 1a and the small diameter portion 1b in accordance with the diameter difference. Therefore, slippage always occurs between the large-diameter portion 1a or the small-diameter portion 1b of the workpiece 1 and the small-diameter portion 2a or the large-diameter portion 2b of the adjustment wheel 2 corresponding to the large-diameter portion 1a or the small-diameter portion 2b. There is a problem that the part of the car 2 wears faster than the other parts and deteriorates the machining accuracy of the workpiece 1 in a short time.

Therefore, as a countermeasure against this, conventionally, the adjustment wheel 2
The method of making the material of the sliding occurrence side of
A method of increasing the friction coefficient of one of the small-diameter portion 2a and the large-diameter portion 2b of the adjusting wheel 2 (see Japanese Patent Publication No. 61-37061), by combining the small-diameter portion 2a and the large-diameter portion 2b of the adjusting wheel 2 Method of splitting and making the small diameter portion 2a side free to rotate (Japanese Patent Publication No. 60108/44108)
And a method of dividing the small diameter portion 2a and the large diameter portion 2b of the adjusting wheel 2 and rotating both at a different peripheral speed (Japanese Patent Application Laid-Open No.
93161) and the like.

[0005]

All of these conventional methods have the following problems. That is, in the former two methods, one of the small-diameter portion 2a and the large-diameter portion 2b of the adjusting wheel 2 is made of a material having high wear resistance or a material having a large friction coefficient. However, it merely extends the time until wear, and there is naturally a limit in preventing the deterioration of processing accuracy, and it cannot be said that this is a sufficient measure.

In the latter two methods, a workpiece 1 and an adjusting wheel 2
Can be prevented from occurring, but there is a disadvantage that the structure becomes very complicated, and it cannot be carried out immediately, particularly in existing centerless grinding machines.

The present invention has been made in view of the above-mentioned conventional problems, and can prevent deterioration of machining accuracy due to abrasion of an adjusting wheel caused by slippage, and can be easily adopted in existing centerless grinding machines and the like. An object of the present invention is to provide a centerless grinding method for a stepped shaft which can increase production capacity without requiring a separate correction time.

[0008]

According to the first aspect of the present invention, there is provided a grinding machine which controls the rotation of a workpiece on a receiving plate by an adjusting wheel having a shape corresponding to a stepped shape of a stepped shaft. In the centerless grinding method of a stepped shaft in which the workpiece 1 is ground by the grindstone 3 to obtain a stepped shaft having a predetermined stepped shape, a small cut amount equal to or more than the wear amount of the adjusting wheel 2 is generated during the grinding process. As described above, the shape of the adjusting wheel 2 for continuously or intermittently correcting the surface shape of the adjusting wheel 2 by cutting the forming tools 5 and 6, and the workpiece 1 by the grinding wheel 3.
Grinding is performed in parallel.

The present invention described in claim 2 provides the present invention in claim 1.
In the invention described in (1), the forming tool 5 is corrected by moving in the axial direction along the shape of the adjusting wheel 2. Further, according to a third aspect of the present invention, in the first aspect, a stepped forming tool 6 corresponding to the shape of the adjusting wheel 2 is used, and the forming tool 6 is moved in the radial direction of the adjusting wheel 2. To correct it.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 illustrate a first embodiment of the present invention.
In this embodiment, the workpiece 1 on the receiving plate 4 is driven by the adjustment wheel 2 rotating in the direction of arrow a, and the rotation of the workpiece 1 in the direction of arrow b is controlled while the workpiece 1 is controlled in the direction of arrow c. The workpiece 1 is ground by the rotating grinding wheel 3 to finish a stepped shaft having a predetermined shape.

During the grinding operation, while the grinding operation is continued without interruption, the forming tool 5 is cut in and the surface shape of the adjusting wheel 2 is corrected by a small amount. That is, the correction of the adjusting wheel 2 by the forming tool 5 is conventionally performed by temporarily suspending the grinding operation. However, the wear of the adjusting wheel 2 caused by the slip with the workpiece 1 does not occur suddenly at a certain point in time, but progresses little by little as compared with the normal.

Then, while the grinding operation is continued without interruption, the forming tool 5 rotating in the direction indicated by the arrow d is brought into contact with the adjusting wheel 2, and the forming tool 5 is cut by a small amount to adjust the adjusting wheel 2. The surface shape of the adjusting wheel 2 is corrected so that the small diameter portion 2a and the large diameter portion 2b have a shape conforming to the step shape of the stepped shaft. That is, the shape correction of the adjusting wheel 2 by the forming tool 5 and the grinding of the workpiece 1 by the grinding wheel 3 are performed in parallel.

In this case, the cutting amount is small, for example, 0.5 to 1 μm so as not to affect the processing accuracy of the stepped shaft to be aimed, and is equal to or less than the wear amount of the adjusting wheel 2. Is repeatedly corrected so as to have a slightly small amount of incision.

Therefore, slippage occurs due to a difference in peripheral speed between the workpiece 1 and the adjusting wheel 2, thereby causing the small-diameter portion of the adjusting wheel 2 to slide.
Even if wear occurs on either the large diameter portion 2a or the large diameter portion 2b, the surface shape of the adjusting wheel 2 is intended to be aimed at by adjusting the surface shape of the adjusting wheel 2 by the forming tool 5 during the grinding operation. It can always be kept in the best condition according to the finished shape of.

For this reason, it is possible to prevent the machining accuracy from being deteriorated due to the wear of the adjusting wheel 2 as in the related art, and at the same time, to perform the adjusting operation which is conventionally performed once a day for about 20 to 30 minutes by interrupting the grinding operation. There is no need to take extra time to correct car 2,
There is also an advantage that the production efficiency is increased. In particular, since the correction of the shape of the adjusting wheel 2 by the forming tool 5 and the grinding of the workpiece 1 by the grinding wheel 3 are performed in parallel, the surface shape of the adjusting wheel 2 can always be maintained in the best condition, and the processing accuracy is significantly improved. There are advantages to In addition, since the centerless grinding machine is usually provided with the forming tool 5, even an existing one can be easily implemented immediately.

In this embodiment, a disk-shaped, column-shaped or cylindrical forming tool 5 having the same diameter over the entire length in the axial direction is used to form an adjusting wheel 2 having a small-diameter portion 2a and a large-diameter portion 2b. The tool is corrected while reciprocating the forming tool 5 in the axial direction along the axis. By moving the forming tool 5 in the axial direction in this way,
There is no need to use a specially shaped forming tool corresponding to the shape of the adjusting wheel 2, and there is an advantage that a simple forming tool 5 can be used.

FIGS. 3 and 4 illustrate a second embodiment of the present invention. A shaping tool 6 having a stepped shape corresponding to the stepped shape of the adjusting wheel 2 is used. To adjust the surface shape of the adjusting wheel 2.

That is, the forming tool 6 is a small-diameter portion 2a of the adjusting wheel 2.
And a large diameter portion 6a and a small diameter portion 6b corresponding to the large diameter portion 2b. Then, while the forming tool 6 is rotated in the direction indicated by the arrow d, it is moved in the radial direction of the adjustment wheel 2 as indicated by the arrow e, and the small diameter portion 2a of the adjustment wheel 2 is changed to the small diameter portion 6b by the large diameter portion 6a. With adjustment car 2
The large-diameter portion 2b is cut by a small amount each, and the distance between the adjusting wheel 2 and the workpiece 1 is simultaneously reduced by the cut amount. Therefore, the adjustment wheel 2 can be used without interrupting the grinding operation.
There is an advantage that the surface of the molding tool 6 can always be kept in the best condition, and the movement of the forming tool 6 can be simplified.

The correction of the surface shape of the adjusting wheel 2 by the forming tools 5 and 6 may be performed continuously during the grinding operation, or may be performed periodically shortly before the processing accuracy deteriorates.
It may be performed intermittently.

[0020]

Further, in the first and second embodiments, the large-diameter portion 1a
Although the case of grinding the rough-processed workpiece 1 having the small-diameter portion 1b and the small-diameter portion 1b has been described, even when the stepped shaft is processed by the form grinding from the round bar-shaped workpiece 1, the adjustment wheel 2 Needless to say, it can be applied to correction.

[0022]

According to the present invention, during the grinding process, the forming tools 5 and 6 are cut so that the surface shape of the adjusting wheel 2 is continuously reduced so that the cutting amount becomes a minute amount equal to or more than the wear amount of the adjusting wheel 2. Or, the shape of the adjusting wheel 2 to be intermittently corrected and the grinding wheel 3
Is performed in parallel with the grinding of the workpiece 1, the deterioration of the processing accuracy due to the wear of the adjusting wheel 2 caused by the slippage can be prevented, and the present invention can be easily adopted in an existing centerless grinding machine or the like. In addition, during the grinding process, the correction of the shape of the adjusting wheel 2 by the forming tool 5 and the grinding of the workpiece 1 by the grinding wheel 3 are performed in parallel.
It is not necessary to take an additional time to correct the data, and the production capacity can be increased accordingly. In addition, correction of the shape of the adjustment wheel 2,
Since the grinding of the workpiece 1 by the grinding wheel 3 is performed in parallel, the surface shape of the adjusting wheel 2 can always be maintained in the best state,
Thereby, there is an advantage that the processing accuracy of the workpiece 1 is significantly improved. Further, since the shape of the adjusting wheel 2 is corrected by cutting the forming tools 5 and 6 with a minute cut amount larger than the wear amount of the adjusting wheel 2, the shape of the adjusting wheel 2 is always and reliably corrected by the forming tools 5 and 6. It can be performed.

[Brief description of the drawings]

FIG. 1 is a front view showing a first embodiment of a centerless grinding method for a stepped shaft according to the present invention.

FIG. 2 is a plan view showing a first embodiment of a centerless grinding method for a stepped shaft according to the present invention.

FIG. 3 is a front view showing a second embodiment of a centerless grinding method for a stepped shaft according to the present invention.

FIG. 4 is a plan view showing a second embodiment of a centerless grinding method for a stepped shaft according to the present invention.

FIG. 5 is a perspective view showing a centerless grinding method for a stepped shaft.

[Explanation of symbols]

 1 Workpiece 2 Adjustment wheel 3 Grinding wheel 4 Receiving plate 5 Forming tool 6 Forming tool

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B24B 5/30

Claims (3)

(57) [Claims] A grinding wheel (3) controls the rotation of a workpiece (1) on a receiving plate (4) while an adjusting wheel (2) having a shape corresponding to the step shape of a stepped shaft controls the workpiece (1). In the stepless shaft centerless grinding method of finishing 1) to form a stepped shaft having a predetermined step shape,
During the grinding process, the forming tools (5) and (6) are cut so that the surface shape of the adjusting wheel (2) is continuously or intermittently cut so that the minute cutting amount is equal to or more than the wear amount of the adjusting wheel (2). A centerless grinding method for a stepped shaft, wherein the correction of the shape of the adjusting wheel (2) to be corrected and the grinding of the workpiece (1) by the grinding wheel (3) are performed in parallel. 2. The method of claim 1, wherein the forming tool (5) is moved in the axial direction along the shape of the adjusting wheel (2) for correction. 3. A shaping tool (6) having a stepped shape corresponding to the shape of the adjusting wheel (2), and the forming tool (6) is connected to the adjusting wheel (2).
The centerless grinding method for a stepped shaft according to claim 1, wherein the correction is performed by moving the stepped shaft in the radial direction.